Selective orificing steam condenser

ABSTRACT

An air cooled steam condenser having plate means or a series of plates mounted within the steam intake header compartment. The plate means in effect form a series of interconnected subchambers, each of which communicates with a row of cooling tubes in which steam is condensed by a stream of cooling air flowing over, around and past the tubes. The rows of tubes extend transversely of the direction of airflow and the rows extend perpendicular to the direction of airflow at spaced intervals. An opening is formed in each plate through which steam flows between sub-chambers. The openings are smaller in area in successive plates in the header through which the steam flows so that only that amount of steam that can be condensed effectively within the tubes in any row, enters such row, having regard to the tube length and the temperature difference at the particular row which determines the cooling effect of the airflow over the successive rows of tubes.

United States Patent [191 Ris a [451 Apr. 30, 1974 SELECTIVE ORIFICINCSTEAM CONDENSER Kenneth B. Ris, Massillon, Ohio [73] Assignee: EcodyneCorporation, Chicago, Ill.

[22] Filed: Jan. 18, 1973 [21] Appl. No.: 321,105

Related U.S. Application Data [62] Division of Ser. No. 126,174, March19, 1971.

[75] Inventor:

Primary Examiner Albert W. Davis, Jr. Attorney, Agent, or Firm-Joel L.Siegel [57] ABSTRACT An air cooled steam condenser having plate means ora series of plates mounted within the steam intake header compartment.The plate means in effect form a series of interconnected subchambers,each of which communicates with a row of cooling tubes in which steam iscondensed by a stream of cooling air flowing over, around and past thetubes. The rows of tubes extend transversely of the direction of airflowand the rows extend perpendicular to the direction of airflow at spacedintervals. An opening is formed in each plate through which steam flowsbetween subchambers. The openings are smaller in area in successiveplates in the header through which the steam flows so that only thatamount of steam that can be condensed effectively within the tubes inany row, enters such row, having regard to the tube length and thetemperature difference at the particular row which determines thecooling effect of the airflow over the successive rows of tubes.

I 4 Claims, 10 Drawing Figures PATENTEDmso I974 sum 3 or 3 Y s&\\\

This is a division, of application Ser. No. 126,174, filed Mar. 19,1971.

BACKGROUND OF THE INVENTION 1. Field of the Invention The inventionrelates to heat exchangers and in particular to air cooled steamcondensers. More particularly the invention relates to orificing meansmounted within the condenser header whereby the amounts of steamentering various rows of condensing tubes are metered or reducedproportionally to the reduced cooling effect of the cooling air due toincreased cooling air temperature resulting from heat extracted fromtubes previously cooled, so that only that amount of steam that can becooled efficiently is supplied to the tubes of a particular row.

2. Description of the Prior Art Air cooled steam condensers usuallyinclude a plurality of condenser tubes arranged in rows one behind theother in the direction of airflow of the cooling air. Steam enters thecondenserinlet header which communicates with the inlet ends of thetubes and then flows through the tubes wherein it is condensed. Fansblow cooling air across the tubes in an airflow direction generallyperpendicular to the rows of tubes. The steam is condensed by the'cooling air to form condensate as it travels through the tubes, and thecondensate is collected at the outlet ends of the tubes in any suitablemanner. Condensation should take place throughout the length of thetubes for most efficient condenser operation.

Problems have arisen in the construction and operation of air cooledsteam condensers as described in US. Pat. No. 3,073,575 relating toinefficient steam feed distribution to the cooling tubes, temperaturedifferential changes due to changing weather conditions, etc. Thevarious solutions to such problems suggested in said U.S. Pat. No.3,073,575, however, are complicated in structure and expensive inexecution.

No air cooled steam condenser constructions of which I am aware haveeliminated the problems of uneven steam distribution by efficientlymetering or distributing the steam within the condenser inlet header bysimple'partition means using simple finned condenser tubes in all rowsof the condenser having the same structure and characteristics as todiameter, length and cooling finsurface.

SUMMARY OF THE INVENTION Objectives of the invention include providingselective orificing for steam condensers which meters the amounts ofsteam flowing to and through the cooling tubes in tube rows of thecondenser, proportional to the condensing ability of the tubes in anyparticular tube row; providing selective orificing for steam condensershaving condenser tubes all of which are the same in length, passagecross section, number of fins, and total heat exchange surface area;providing selective orificing for steam condensers in which plateshaving openings of varying sizes are mounted within the condenser inletheader for selective distribution of steam; providing selectiveorificing for steam condensers permitting existing condenser designs tobe converted easily and inexpensively to establish predetermined metereddistribution of steam to the several rows of cooling tubes in thecondenser; and providing selective orificing for steam condensers whicheliminate difficulties heretofore encountered, achieve the statedobjectives simply and effectively, and solve problems and satisfyexisting needs.

These objectives and advantages are obtained by the selective orificingconstruction for steam condensers, the general nature of which may bestated as including in a steam condenser for condensing steam in. aplurality of tubes arranged in a plurality of generally parallel rows,extending between and communicating with a steam inlet header and acondensate outlet header; the

rows of tubes extending transversely of and at spaced intervalsperpendicular to the direction of airflow of cooling air that passesover and around the rows of tubes to condense steam flowing through thetubes from the inlet header; the steam inlet header having a chamber andinlet means for said chamber; partition means mounted within the chamberdividing the chamber into a series of metered steam zones eachcommunicating with at least one row of tubes; said partition means beingconstructed to distribute inlet steam in the chamber in successivelysmaller amounts to each successive zone corresponding to the reducedcooling effect of the airflow of cooling air passing successively overthe spaced rows of tubes to which steam is distributedfrom successivezones; means preferably including a plurality of partition platesdividing the chamber into a plurality of sub-chambers forming saidsuccessive zones and communicating respectively with successive rows oftubes; an opening formed in each plate for supplying steam from onesub-chamber zone to the adjacent sub-chamber zone; and the openings insuccessive plates between adjacent sub-chamber zones being successivelysmaller.

In' the alternative the -partition means may include a partition platelocated in the inlet header angularly BRIEF DESCRIPTION OF THE DRAWINGSPreferred embodiments of the invention illustrative of the best modes inwhich applicant has contemplated applying the principles are set forthin the following description and shown in the drawings and areparticularly and distinctly pointed out and set forth in theappendedclaims.

FIG. 1 is a perspective view, with portions broken away, showing an aircooled steam condenser equipped with the improved selective orificingplate construction;

FIG. 2 is a diagrammatical side elevation of the steam condenser shownin FIG. 1;

FIG. 3 is an enlarged fragmentary top plan view, with portions brokenaway and in section, looking in the direction of arrows 3-3, FIG. 2 andshowing one condenser section;

FIG. 4 is a sectional view taken on line 4-4, FIG. 3;

FIG. 5 is an enlarged sectional view taken on line 5-5, FIG. 3;

FIG. 6 is a further enlarged fragmentary sectional view taken on line6-6, FIG. 5;

FIG. 7 is a fragmentary top plan view, with portions broken away and insection, showing a modified steam condenser Construction having acylindrical steam drum or header equipped with improved selectiveorificing plate means;

FIG. 8 is a sectional view taken on line 88, FIG. 7;

FIG. 9 is an enlarged fragmentary sectional view taken on line 99, FIG.7; and

FIG. is a view similar to FIG. 9 showing a modified form ofconstruction.

Similar numerals refer to similar parts throughout the drawings.

DESCRIPTION OF PREFERRED EMBODIMENTS First Embodiment A typical aircooled heat exchanger is indicated at 1, (FIGS. 1 and 2) and includestwo steam condenser sections 2 and 3 supported on frame members 4 andhaving side and end panels 5 mounted on the frame members 4. Fans 6mounted on pedestals 7 beneath condenser sections 2 and 3 blow coolingair (indicated by arrows A, FIG. 2) upward through sections 2 and 3.

A steam supply manifold 8 communicates with a source of steam, such asthe exhaust of a steam turbine, to be condensed, and pipes 9 form steaminlets for the individual sections 2 and 3 from manifold 8. Condensateoutlet lines 11 are connected to the opposite ends of sections 2 and 3and deliver condensate into a main condensate line 12.

Different heat exchanger installations may have a different number ofcondenser sections 2 and 3 assembled together. The operation andfunction of condenser sections each having the improved selectiveorificing means incorporated therein are similar. Therefore only onecondenser section 2 (FIGS. 3-6) is described in detail.

Condenser section 2 includes a plurality of cooling tubes 13 preferablyhaving helical fins 14 extending outward therefrom. Tubes 13 are mountedwithin a frame having side channels 10, an inlet header 15 and an outletheader l6.

Tubes 13 are mounted parallel to each other within the frame in aplurality of rows 17, 18, 19 and 20 spaced one above the other (FIGS. 4,5 and 6) arranged in that order along the direction of flow indicated bythe arrow A. Tubes 13 in a particular row may be spaced intermediate thetubes in the adjacent rows, above and below, as shown in FIG. 5.Likewise, tubes 13 are assembled within the frame so as to have a slightincline from inlet header 15 to outlet header 16 so that condensateflows or drains into header 16.

Inlet header 15 may have a welded construction as shown in US. Pat. No.3,582,599, granted June 1, 1971 of Melvin G. Yohn. Such construction mayinclude a generally rectangular cross section formed by top and bottomwalls 21 and 22, tubesheet 23, plug sheet 24, and end walls 25. Theinlet ends of tubes 13 are connected in a usual manner by expending orwelding in tubesheet 23; and holes 27 in plug sheet 24 aligned withtubes 13 permit access into header 15 and tubes 13 for expending orwelding tubes 13 into the header and for cleaning and for removing anyobstructions that may form in tubes 13.

A flanged coupling connected to header bottom wall 22 forms a steaminlet opening for header 15. Coupling 29 has a flange 31 for connectionwith steam inlet pipe coupling 32 of pipe 9 by bolts 32a.

Condensate outlet header 16 may be constructed similar to header 15having aligned holes 33 and 34 formed in tubesheet 35 and plug sheet 36for expanding or welding the outlet ends of tubes 13 in holes 33 and forremovable plugs 37 for access holes 34. Outlet opening 38 in bottom wall39 0f header 16 is connected by flanged coupling 40 with coupling 41 oncondensate outlet line 11.

In accordance with the invention a plurality of partition plates 42, 43and 44 are mounted within header 15 extending between tubesheet 23 andplug sheet 24 and attached by welds 45. The plates 42, 43 and 44 areparallel to each other and to bottom wall 22, and are mounted betweentube rows 17 and 18, 18 and 19, and 19 and 20, respectively. Thussub-chambers 46, 47, 48 and 49 are formed within header l5. Openings 50,51 and 52 are formed in plates 42 and 43 and 44, respectively, withopening 50 being larger in area than opening 51, and opening 51 beinglarger in area than opening 52. The openings 50, 51 and 52 are shown asbeing circular. However, they may have any desired shape to obtain therequired area and may be square, rectangular or elliptical.

Steam flow, indicated by arrow B (FIG. 6), enters header 15 throughdistribution pipe 9 and inlet opening 30. The amount of steam thatpasses through subchambers 46-49 and subsequently rows 17-20 of tubes13, respectively, becomes decreasingly smaller due to the decreasingsize of openings 50-52.

Therefore, a larger amount of steam B, enters the tubes in row 17 forcondensation therein than the reduced amount of steam B entering tuberow 18, and likewise the further reduced amounts of steam B and Bentering tube rows 19 and 20. This continual reduction in amounts ofsteam entering succeeding tube rows of similar tubes spaced along thedirection of flow A of the cooling air, is a characteristic of theconcept of the invention. This compensates for the continual increase intemperature of the air and the decreasing mean effective temperaturedifference as the air passes from row 17 over the subsequent rows 18-20picking up heat from the previously cooled rows of tubes.

The areas of openings 50-52 are determined in designing any particularinstallation by taking into consideration factors including the averagepressure and temperature of the steam entering header 15, the velocityand average temperature of cooling air flowing at A past the tubes 13,and the total finned heat exchange cooling surface of tubes 13. Ideally,the areas of openings 50-52 will be such that the amounts of steamB,-B., entering the respective rows 17, 18, 19 and 20 of tubes 13 willbe completely condensed as steam flow in any tube 13 reaches the outletheader 16.

SECOND EMBODIMENT A modified selective orificing steam condenserconstruction indicated at 53 is shown in FIGS. 7-9 having a cylindricalsteam manifold or header 54 provided with a header inlet section 55communicating with the inlet tubesheet 63 of the condenser. Header 54 ismounted in a cradle support structure 56, and header section 55 may beformed by plates 57, 58, and 61 secured by welds 59 to header 54.

Header section 55 is provided with a flange 62 which is connected in asuitable manner with tubesheet 63, as

shown in FIG. 9. The connection may be sealed by a gasket 64.

Rows of tubes 6568 each having a plurality of tubes 69, have their inletends connected to tubesheet 63 and communicate with header inlet section55. Tubes 69 otherwise are arranged like tubes 13 in condenser l andcooling air flows past tubes 69 as indicated at C.

A partition plate 70 is mounted within the header inlet section 55 ofthe header compartment of header 54, preferably by welding the plate 70at 71 to header inlet section plates 60, 57 and 58 (FIG. 9). Plate 70extends outwardly downwardly at an angle away from tubesheet 63, and thelower or free edge 70a of plate 70 is spaced above plate 61 of headersection 55 to form a passage 73 communicating between the headercompartment and header sub-chamber 72-located between partition plate 70and the inlet ends of tubes'69.

The angular arrangement of partition plate 70 with respect to tubesheet63 forms a series of zones in subchamber 72 of decreasing size frombottom to top (FIG. 9) opposite the inlet ends of the rows 65, 66, 67and 68 of tubes 69. This series of zones of decreasing size meters theamounts of steam flowing into tube rows 65-68 in decreasing amounts, asindicated at D-l, D2, D3 and D-4, and distributed from the main steamflow indicated at D entering the sub-chamber 72 from the inlet header54.

Partition plate 70 thus forms a partition means defining in the header54 and header section 55 a passage 73 and a series of successivelysmaller tube inlet zones communicating respectively with the successiverows of tubes 65-68.

The amounts of steam entering the various rows can be changed bychanging the angle of projection of plate 70, thereby changing thecapacity of sub-chamber 72. The flow C of cooling air is in a directionacross the rows 65-68 of tubes 69 such that row 65, which receives thegreatest amount of steam, is cooled by the coolest air. If for somereason the direction of airflow C is from top to bottom in FIG. 9, plate70 would project upwardly outwardly with respect to tubesheet 63'fromplate 61.

THIRD EMBODIMENT The construction shown in FIG. 10 is similar to thatshown in FIG. 9 excepting that the partition plate 74 may be curved, asshown, rather than a flat plate 70 as illustrated in FIG. 9. The curvedshape may be designed so that the respective series of zones ofdecreasing size in sub-chamber 75 will have the required size or volumeto obtain the steam distribution pattern to be achieved in the design ofthe sub-chamber 75.

IN GENERAL In each of the embodiments of the invention illustrated inthe drawings and described above, partition and inexpensively convertedto include the improved selective orificing construction; enablesmaximum efficiency to be achieved in the operation of the condenser;prevents premature condensation which may result in frozen conditionsduring cold weather; and provides such a construction which iseffective, safe, inexpensive, and efficient in assembly, operation anduse, and which achieves all the enumerated objectives, provides foreliminating difficulties encountered with prior devices, and solvesproblems and obtains new results in the art.

In the foregoing description, certain terms have been used for brevity,clearness and understanding but no unnecessary limitations are to beimplied therefrom beyond the requirements of the prior art, because suchterms are used for descriptive purposes and are intended to be broadlyconstrued.

Moreover, the description and illustration of the invention is by way ofexample, and the scope of the invention is not limited 'to the exactdetails of the construction shown or-described.

Having now described the features, discoveries and principles of theinvention, the manner in which the improved selective orificing steamcondenser is constructed, assembled and operated, the characteristics ofthe new construction, and the advantageous, new and useful resultsobtained; the new and useful structures, devices, elements,arrangements, parts, and combinations are set forth in the appendedclaims.

I claim:

1. In a steam condenser of a type in which a plurality of tubes arearranged in a plurality of generally parallel rows, extending betweenand communicating with a steam inlet header and a condensate outletheader; and in which the rows of tubes extend transversely of and atspaced intervals perpendicular to the direction of air flow of coolingair that passes over and around the rows of tubes to condense steamflowing through the tubes from the inlet to the outlet header; the steaminlet header having a chamber and inlet means for said chamber; atubesheet to which the rows of tubes are connected; partition meansmounted within said chamber dividing the chamber into a series ofmetered steam zones each communicating with at least one row of tubes;said partition means including a plate mounted within the inlet headerextending from a location adjacent the last row of tubes to receivecooling air outwardly away from the tubesheet to a location spaced froma header wall to define a passage in said header; said plate defining aseries of successively smaller tube inlet zones communicatingrespectively with successive rows of tubes in said header so as todistribute inlet steam in said chamber in successively smaller amountsto each successive zone corresponding to the reduced cooling effect ofthe air flow of cooling air passing suc- 8 which communicaterespectively with the successive rows of tubes.

3. The construction defined in claim I in which the plate is flat.

4. The construction defined in claim 1 in which the plate is curved.

1. In a steam condenser of a type in which a plurality of tubes arearranged in a plurality of generally parallel rows, extending betweenand communicating with a steam inlet header and a condensate outletheader; and in which the rows of tubes extend transversely of and atspaced intervals perpendicular to the direction of air flow of coolingair that passes over and around the rows of tuBes to condense steamflowing through the tubes from the inlet to the outlet header; the steaminlet header having a chamber and inlet means for said chamber; atubesheet to which the rows of tubes are connected; partition meansmounted within said chamber dividing the chamber into a series ofmetered steam zones each communicating with at least one row of tubes;said partition means including a plate mounted within the inlet headerextending from a location adjacent the last row of tubes to receivecooling air outwardly away from the tubesheet to a location spaced froma header wall to define a passage in said header; said plate defining aseries of successively smaller tube inlet zones communicatingrespectively with successive rows of tubes in said header so as todistribute inlet steam in said chamber in successively smaller amountsto each successive zone corresponding to the reduced cooling effect ofthe air flow of cooling air passing successively over the spaced rows oftubes to which steam is distributed from successive zones.
 2. Theconstruction defined in claim 1 in which the inlet header is formed by acylindrical steam manifold and an inlet header section; in which theplate mounted within the header section forms a sub-chamber between thetubesheet and plate; and in which the sub-chamber forms the successivelysmaller inlet zones which communicate respectively with the successiverows of tubes.
 3. The construction defined in claim 1 in which the plateis flat.
 4. The construction defined in claim 1 in which the plate iscurved.